Drifting-valve



MH. HANLUN.

UHIFUNG VALVE.

MFUCMLUN HIJ-.U UCI'. 30. HHS.

fgfy-SG. Patented May 17, 192i.

) To asma if() MNN VALVE 6 0 TRW CYUNDER JOHN H. H BNLON, 0F SOMEB'VILLE, MASSACHUSETTS.

DRIFTmG-VALETE.

Specicaton of Letters atent.

Patented nay iv, 192i.

Application led Uctober 30, 1918. Serial No. 263,222.

Vfor use on steam locomotives by which wet or saturated steam will be furnished to the working cylinders of the locomotive during the time when the locomotive is in motion but is not being supplied with steam through the dry pipe. The use and functions of drifting valves of the type mentioned are well understood hy those skilled in the art and, therefore will not be described detail here.V The present invention is an improvement of the drifting valve shown in my rior application for United States Letters atent filed Got. 24, 1917 Serial No. 198,217 to which reference may be had. The driiting valve formino` the subject matter of my present invention is simpler in construction and more reliable in its operation than the valve shown in my prior application. lt does, however, embody the essential features of the drifting valve therein shown.

The invention will he fully understood from the following description when taken in connection with the accompanying drawings and the novel features thereof will be pointed out and clearly defined in the claims atthe close of this specification.

"In the drawings, Figure 1 is a side elevation of a locomotive to which is applied a drifting valve embodying mv invention.

Fig. 2 is a vertical section of the main valve and operating mechanism.

Fig. 3 vis a vertical section taken on line 3--3 of Fig. 2.

Fig. l is a vertical section of the secondary valve.

Referring now to the drawingsr the main valve casing is indicated at '14 and the main valve at 15. The secondary valve casing is designated 16 and the valve 'is designated 17. rlhe main valve casing' is connected by a pipe 18 with the boiler. The casing is also connected by the pipes 19 and 2O with the two working cylinders ofv the locomotive only one cylinder being shown in the drawings. The steam passage a'orded hy the pipe 19 also leads through the secondary valve 16, said secondary valve being conveniently located on the top ci the steam chest. it 21 is shown a pipe leading roin thesecondary valve casing 16 to the trip cylinder 22. The piston 23 ci the trip cylinder 22 is moved toward the left as seen in Fig. 3 by a spring 24 surrounding a rod 25 and is moved in the other direction by a steam pressure within the trip cylinder 22.

The main valve l5 is providedwith an auxiliary valve'171 which opens irst and hy admitting steam to the space 38 beneath the piston-shaped lower end 39 of the main valve 15 equalizes the pressure on both sides of the main valve so that the main valve may be lifted with less eiort. The main valve is lifted hy a plunger 26, the stein of which extends through a stutling box 27 and into the path oi a cam 28 having a tail g which is acted upon by the throttle lever 29 through the interposition of a swinging dog 30 pivoted at 31 to the bracket 32 which sup-V ports the mechanism.

The tension on the spring 24 is adjusted by means of the thimble 83 and check nut 34.

The secondary valve which is placed on the top of the locomotive cylinder has a movable valve member 17 which is normally open. ln the drawings,- have shown the valve as placed vertically so that the valve is held open hy the action of gravity but other means may be provided it the valve is in a dilerent location. This valve member 17 engages a valve seat aand closes the passage leading from the main valve to the locomotive cylinders. The pipe 21 which leads to the trip cylinder connects with a port 35 which intercepts the valve seat a and therefore is closed whenever the secondary valve is on its seat. At 36 is shown a bleeder port hy which the steam between the main valve and the secondary valve may escape to the atmosphere and at 37 is shown another bleeder port by which the steam in the trip cylinder and the pipe leading` to it may escape to the atmosphere. This port is of an area much smaller than that ci port 35 so that the escape of steam through port 37 will not prevent the accumulation ci pressure in the trip cylinder as long as valve 17 is open.

My improved drifting valve operates in Gti the following manner: As long as the locomotive is running with open throttle, the main valve l5 and the secondary valve 16 remain closed, duc to the pressure on the upper side ot the main valve l5 and on the lower side of the secondary valve member 17 respectively. Since these valves are closed, no steam can reach the trip cylinder 2f. lllhen the engineer shuts od the throttle on beginning,r to go down grade, the throttle moves the dop,- 30 which in turn moves the tail g ot the cam 28 opening the main valve le. Wvhen the Vmain valve il is opened, steam passes through the pipe i9 and sccondary valve 16 to the locomotive cylinder.

is long' as the locomotive is running the suction in the locomotive Will cause the steam to low freely into the locomotive cylinders and no back pressure will be built up. The trip cylinder will, therefore, remain in the position shown in Fig. 3 as long as the locomotive continues to move. As soon as the locomotive ceases moving, pressure Will be built up and steam will enter the trip cylinder through the port 35 andl pipe 2l. The trip cylinder is designed in size to be sensitive to a pressure less than that which is likely to cause the locomotive to move. ln practice l design it so that the trip cylinder will move when the pressure reaches about fifteen pounds to the square inch. 1When this pressure is attained the piston moves to the right out from under the plunger 26 and the main valve lcloses shutting' oli the supply ot steam to the locomotive cylinders. The bleeder port 36 then reduces the pressure in the pipe 19. At the same time the steam in the trip cylinder escapes through the bleeder port 37. As soon as the pressure in the trip cylinder 22 has been reduced sutiiciently the spring 2a pushes back the piston 23 and replaces the cam 28 under the end of the plunger 2.6 resetting the device. When steam is nent admitted to the Working cylinders of the locomotive the increase in pressure immediately seats the valve 17 so that there can beno leakage from the cylinders at this point.

What l' claim is:

l. ln a device of the character described,

Va main valve controlling a steam passage leading from the boiler to the cylinders of the locomotive, throttle actuated mechanism 4to open said main valve by the movement which closes the throttle, a trip cylinder operatively connected with said main valve and connections to the trip cylinder entering said steam passage at a point nea-r the cylinders ot the locomotive whereby an accumulation or" pressure in the cylinders of the locomotive will produce pressure in the trip cylinder and actuate the trip cylinder to permit the closirg of the said main valve.

2. n a device of the character described, a main valve controlling a steam passage Y nevar/ee leading from the boiler to the cylinders or" the locomotive, throttle actuated mechanism to open said main valve by the movement which closes the throttle, a trip cylinder operatively connected with said main valve. connections to the trip cylinderentering said steam passage at a point near the cylinders of the locomotive, and a valve in said steam passage operated by accumulation of pressure in the locomotive cylinders to close said steam passage Whenever the throttle is open.

3. ln a de tice ot the character described7 a main valve, a casing therefor, connections ary valve and casing' therefor, a trip cylinder operatively connected with said main valve, steam connections connecting the boiler with the main valve casing, the main valve casing' with the locomotive cylinders through the secondary valve casing, and the secondary valve casing; with the trip cylinder, and throttle operated means tor opening the main valve by the closing movement ot' the throttle, said main valve being released by the trip cylinder and thereby permitted to close upon accumulation of pressure in the trip cylinder.

5. ln a device ot the character described, a main valve and casing therefor, a secondary valve and casing therefor, a trip cylinder operatively connected with 'said main valve and releasing said 'main valve and permitting it 'to close upon accumulation of pressure in said trip cylinder, steam connections connecting' the boiler with the main valve casing', the main Vvalve casing With the locomotive cylinders through the secondary valve casing, and the secondary valve casing with the trip cylinder, said steam connection to the 'trip cylinder entering the steam connection 'from the main valve to the locomotive cylinder through the valve seat ot the secondary valve so that the said valve member controls both steam passages.

6. lin a device ot the character described, a main valve and casing therefor, a secondary valve and casing therefor, a trip cylinder operatively connected with said main valve and releasing said main valve and permitting it to close upon accumulation ot pressure in said trip cylinder, steam connections connectinp, the boiler with the main valve easlOG ing, the main valve casing with the locomosecondary valve so that the sai valve memtive cylinders through the secondary valve ber contros both steam passages, there casing, and the secondary valve casing with being a. bleeder port connecting the trip 10 the trip cylinder, said `steam oonnectlon to,` cylinder passages with the atmosphere. 5 the trip cylinder entering the steam connec- In testxmony whereof I ax my signature.

tion from the main valve to the locomotive v o e cylinder through the valve seat of the JOHN H. HANLON. 

